Human-machine interface (“HMI”) devices are typically used in industrial settings to configure setup parameters of industrial equipment and to display data provided from the industrial equipment. One such industrial equipment is power-metering equipment which monitors power signals in an electrical circuit. To obtain data and to configure setup parameters, an HMI device is attached to the power-metering equipment or is remotely tethered to it via an umbilical cable carrying communication and optional power signals between the HMI device and the power-metering equipment. The HMI device typically runs a menu-driven software program with which the operator interacts to configure setup parameters or to display data about the power signals monitored by the power-metering equipment. To navigate through the menu, the operator must push a button or a key on the HMI device or touch designated areas on a touchscreen overlaying the display of the HMI device. This manner of interacting with the HMI device is time-consuming and often confusing to the operator who may easily lose the way through a complex menu tree.
For example, if an operator is buried deep within a particular menu and wants to access a different menu, the operator must typically press one or more keys multiple times to navigate to the desired menu screen. Furthermore, the presence of a keypad or buttons on the HMI device poses a limitation on how small the HMI device can be built. Eliminating or reducing the keypad or buttons on the HMI device would allow its form factor to be reduced or would allow a larger display to be installed without increasing bulk.
One way to eliminate the need to navigate through a menu by pressing buttons or keys is to permit such navigation by speech recognition. The operator would simply speak a keyword which would be analyzed and converted by software into a digital information understandable to the microprocessor. The disadvantage to this approach is that voice-recognition software is expensive and requires a fast microprocessor to process spoken sounds without a significant delay.
What is needed, therefore, is an HMI device which overcomes these and other disadvantages. The present invention is directed to satisfying this and other needs.